public Test()
        {
          

        
   IUnityContainer unityContainer = new UnityContainer();
            unityContainer.RegisterType<DbContext, Model.DefaultDbContext>("DefaultDbContext");
            var dbContext = unityContainer.Resolve<DbContext>("DefaultDbContext");

}

private IUnityContainer  unityContainer = null;

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直接一个静态只读

C#单例＝静态只读

上面这个等的也不知道是不是有问题，但是我确实在一本《.net面试宝典》的书上见过单例模式的写法
static readOnly



------解决方案--------------------

也可以写在Gloable.asax

------解决方案--------------------

嗯，改了昵称过来，灌水。

------解决方案--------------------

C# code
        private const string AppContainerKey = "APPLICATION_CONTAINER";

        protected void Application_Start(object sender, EventArgs e)
        {
            IUnityContainer applicationContainer = new UnityContainer();
            applicationContainer.LoadConfiguration();
            ApplicationContainer = applicationContainer;
        }

        public IUnityContainer ApplicationContainer
        {
            get
            {
                return (IUnityContainer)this.Application[AppContainerKey];
            }
            set
            {
                this.Application[AppContainerKey] = value;
            }
        }
//使用 namespace.ApplicationContainer得到实例